Mecyclothorax refulgens, Liebherr, James K., 2015

Liebherr, James K., 2015, The Mecyclothorax beetles (Coleoptera, Carabidae, Moriomorphini) of Haleakala-, Maui: Keystone of a hyperdiverse Hawaiian radiation, ZooKeys 544, pp. 1-407 : 157-159

Taxon classification Animalia Coleoptera Carabidae

(064) Mecyclothorax refulgens sp. n. Figs 81C, 85

Diagnosis.

This and Mecyclothorax semistriatus , comprise the pair of Mecyclothorax argutor group species characterized by contrastingly pale elytral margins and shallow elytral striae. This species (Fig. 81C) can be told from Mecyclothorax semistriatus (Fig. 81B) by the broadly paler pronotal and elytral lateral margins, and the basally narrower elytra, the elytral shape distinctly ovoid with the greatest width well behind midlength. Also, beetles of this species exhibit more well-developed microsculpture, with the elytral disc subiridescent due to the well-developed transverse and isodiametric sculpticells. The discal elytral striae are less punctate in this species, with only the sutural stria punctate basally, striae 2-5 at most slightly irregular. The sutural and 2nd striae are of subequal depth only at the extreme apex of the elytra. More basally the sutural stria is broader and deeper. Setal formula 2 2 2 2. Standardized body length 4.8 mm.

Description

(n = 1). Head capsule with frontal grooves broad near clypeus, a sinuous lateral carina extended to anterior supraorbital seta; dorsal surface of neck flat; eyes moderately convex, ocular lobe moderately protruded from gena, ocular ratio = 1.46, ocular lobe ratio = 0.79; labral anterior margin broadly, shallowly emarginate; antennae filiform, antennomere 3 sparsely setose; mentum tooth with sides acute, apex tightly rounded. Pronotum cordate, little transverse, MPW/PL = 1.19, lateral margins distinctly sinuate before very slightly acute, projected hind angles; pronotal base narrow, MPW/BPW = 1.63; median base depressed relative to disc, 12-14 punctures laterally plus wrinkles present along juncture with disc; basal margin straight; median longitudinal impression fine, very shallow; anterior transverse impression broad, shallow medially, crossed by longitudinal wrinkles, deep, continuous in lateral 2/3; anterior callosity slightly convex, longitudinal wrinkles indistinct; front angles slightly projected, tightly rounded; pronotal apical width greater than basal width, APW/BPW = 1.10; lateral marginal depression narrow throughout, margin upturned to beaded; laterobasal depression moderately broad, slightly raised medially. Proepisternum with 6 punctures along hind marginal groove; prosternal process medially concave, margin smoothly upraised. Elytra convex, sides depressed; basal groove meeting lateral marginal depression at subangulate humerus; elytra narrow basally, MEW/HuW = 2.10; parascutellar seta present; parascutellar striole shallow, smooth, with 1-2 punctures; sutural interval more convex than lateral intervals, the sutural juncture up raised; sutural stria deeper and more punctate than 2nd stria on disc, discal striae 3-5 traceable, smooth, stria 6 obsolete, stria 7 absent, associated intervals broadly, slightly convex on disc, flat laterally; 8th interval laterad position of 7th stria not more convex than more medial elytral surface; 2 dorsal elytral setae at 0.23 –0.29× and 0.66 × elytral length, setal impressions shallow, broad, spanning interval 3; apical and subapical setae present; lateral elytral setae arranged in anterior series of 7 setae and posterior series of 6 setae; elytral marginal depression narrow, margin upturned; subapical sinuation shallow, broad. Mesepisternum with ~8 punctures in 2-3 rows; metepisternal width to length ratio = 0.79; metepisternum/metepimeron suture distinct. Abdomen with shallow, indistinct lateral wrinkles on ventrites 1-3; suture between ventrites 2 and 3 complete; apical female ventrite with 4 equally spaced setae and median pair of 2 small setae along ventrite margin. Legs-metatarsomere 1/metatibial length ratio = 0.18; metatarsomere 4 length along outer lobe 1.4 × medial tarsomere length, apical and subapical setae present; metatarsal dorsolateral sulci narrow, canaliculated, median carina broad. Microsculpture of vertex isodiametric sculpticells in transverse rows; pronotal disc with transverse mesh and parallel lines, median base with distinct isodiametric sculpticells; elytral apex covered with reflective transverse mesh; metasternum with reflective transverse mesh; laterobasal abdominal ventrites with swirling isodiametric and transverse microsculpture. Coloration of vertex rufobrunneous with piceous cast; antennomeres 1-3 flavous, 4-11 rufobrunneous; pronotal disc rufopiceous, lateral margins and pronotal base broadly rufoflavous; proepipleuron rufoflavous, proepisternum rufobrunneous with piceous cast; elytral disc reflective rufopiceous, sutural interval rufous basally, flavous apically; elytral margins broadly paler, intervals 8-9 rufoflavous to flavous at marginal depression, elytral apex broadly rufoflavous to flavous apicad subapical sinuation; elytral epipleuron flavous, metepisternum rufobrunneous with piceous cast; abdomen with ventrites 1-2 and base of 3 piceous, apex of 3 rufoflavous, ventrites 4-6 flavous; metafemur flavous; metatibia rufoflavous.

Female reproductive tract. The lone female specimen was not dissected.

Holotype.

Female (BPBM) labeled: HAWAIIAN IS.: Maui I: / Kipahulu Valley: West Camp; / 12.vii.1983 // at night on tree trunks / F.G. Howarth, Col. / BISHOP Museum // HOLOTYPE / Mecyclothorax / refulgens / Liebherr / det. J.K. Liebherr 2015 (black-margined red label).

Etymology.

The dorsal body surface of these beetles is quite reflective, leading to use of the present participle of the Latin verb refulgeo-to shine-as the species epithet. The nominative singular participle refulgens maintains its ending regardless of gender.

Distribution and habitat.

Mecyclothorax refulgens is distributed in upper Kīpahulu Valley (Fig. 85), 1860 m elevation. The type specimen was collected from a tree trunk at night.